Research Associate in Exoplanet Modelling
University of Cambridge, United Kingdom
Starting in Feburary 2026
Postdoc research associate working with Oli Shorttle at the Institute of Astronomy.
Investgating the role of volatile chemistry, solubility, and radiative properties in setting the observable properties of sub-Neptune/super-Earth planets that are being observed.
DPhil in Atmospheric Oceanic and Planetary Physics
University of Oxford, United Kingdom
October 2022 — January 2026
Currently in my final year of the DPhil programme in atmospheric physics, supervised by Ray Pierrehumbert and co-supervised by Tim Lichtenberg.
I research the coupled interior-atmosphere evolution of rocky (exo)planets, aiming to understand how the physics of these systems shapes their evolution through delicate feedback processes. This research takes the form of numerical modelling, which is then compared to telescope observations.
MPhys in Physics
University of Exeter, United Kingdom
September 2018 — July 2022
Four-year integrated MPhys Physics programme completed with a 1st (final grade of 85%).
Modules included: astrophysics, electromagnetism, analytical dynamics, thermodynamics, scientific programming, and extensive partnered lab work.
My dissertation project was published in MNRAS as Nicholls et al. (2023).
Volatile-rich evolution of molten super-Earth L 98-59 d
Nicholls, Lichtenberg, Chatterjee, Guimond, Pierrehumbert (2025d)
In review, arxiv:2507.02656
I study the evolution of the super-Earth L 98-59 d from its formation up to the present day. Including atmospheric escape alongside my real-gas atmosphere structure model, I reproduce JWST observations of its hybrid H2-H2S-SO2 atmosphere.
These results indicate a volatile-rich and geochemically-reducing birth scenario, inviting a more nuanced classification framework for small planets beyond the 'water world' and 'gas dwarf' paradigms.
Presented at Exoclimes VII.
Self-limited tidal heating and prolonged magma oceans in the L 98-59 system
Nicholls, Guimond, Hay, Chatterjee, Lichtenberg, Pierrehumbert (2025c)
Published in MNRAS, doi:10.1093/mnras/staf1167, arxiv:2505.03604
Observations of L 98-59 indicate that it hosts three planets with large orbital eccentricities. I calculate the tidal heating within these planets self-consistently with outgassing and atmospheric energy transport.
A robust feedback between tidal heating, radiative cooling, and mantle rheology leads to self-regulation of tidal heating. Tidal heating may allow them remain molten for a long time, and raises the potential for 'tidally supported worlds'.
AGNI: A radiative-convective model for lava planet atmospheres
Nicholls, Pierrehumbert, Lichtenberg (2025b)
Published in JOSS, doi:10.21105/joss.07726, arxiv:2506.00091
Accurate models for the atmospheres of lava planets are critical for understanding their evolution and present states.
I present a new radiative-convective real-gas atmosphere model for lava planets. This model is designed to be flexible and accurate, allowing for rapid exploration of parameter spaces while including a suite of physical processes.
Convective shutdown in the atmospheres of lava worlds
Nicholls, Pierrehumbert, Lichtenberg, Soucasse, Smeets (2025a)
Published in MNRAS, doi:10.1093/mnras/stae2772, arxiv:2412.11987
Using a new radiative-convective atmosphere model 'AGNI', I found that atmospheres on permanent lava worlds can be convectively stable.
Absorption features of CO2 and SO2 within emission spectra are associated with mantle redox state. Presented at UKPF Meeting 2025.
Magma Ocean Evolution at Arbitrary Redox State
Nicholls, Lichtenberg, Bower, Pierrehumbert (2024)
Published in JGR Planets, doi:10.1029/2024JE008576, arxiv:2411.19137
With a new interior-atmosphere modelling framework 'PROTEUS', I simulated the evolution and cooling of primordial terrestrial magma oceans.
The greenhouse effect of outgassed atmospheres exerts significant control over magma ocean cooling and crystallisation. Presented at EGU 2024.
Self-Consistent Modelling of Flares and Gas Giants
Nicholls, Hebrard, Venot, Drummond, Evans (2023)
Published in MNRAS, 10.1093/mnras/stad1734, arxiv:2306.03673
Using a radiative-convective photochemical kinetics model, I found that flares induce observable features in the spectra of sufficiently cool gas giants orbiting M-stars.
Presented at Exoclimes VI.
Reviewer for academic journal
Winter 2024 — Spring 2025
I have been a reviewer for the Planetary Science Journal, providing feedback on articles concerning atmospheric energy transport in exoplanet atmospheres.
Co-supervision of two undergraduate BSc projects
Spring 2025 — Ongoing, Groningen
Co-supervision of two undergraduate astronomy students. Projects currently in progress.
Co-supervision of undergraduate BSc project
Spring — Summer 2024, Groningen
This project aimed to test the robustnest of the canonical runaway greenhouse effect, considering different secondary atmosphere compositions. We then worked to turn their thesis into a paper, published in ApJ.
I guided the student through the research project, including the use of computer simulations and statistical analysis, and provided feedback and assessment of their dissertation at the end of the project.
Undergraduate lab teaching
Autumn 2023 — Summer 2025, Oxford
Demonstrating electromagnetism lab experiments to undergraduate students at Oxford. The experiments involve calculating various physical constants, and demonstrating known relationships such as Faraday’s Law. Demonstrating in labs has taught me several skills, particularly on providing instructions and constructive feedback.
Primary school outreach programme
Autumn 2022, Oxford
I visited two primary schools to engage Year 5 children with workshops on general physics. Introduced a class of 30 to broader concepts, and then worked with groups to conduct small experiments.
Summer research project
June 2020 — August 2020, Exeter
Using proprietary FDTD software and open source data science libraries, I optimised photonic crystal cavities for the desired characteristics. My code was later applied to other photonic systems by the research group at Exeter.
Internship at semiconductor company
June 2019 — August 2019
I was involved with the development of gallium nitride micro-LED display technology with the process engineering group. This included operation of plasma etch tools, as well as developing novel methods for colour conversion using quantum dots.